An adult site is the only thing that I can think of that fits, but that does not appear to be a good fit for your profile.
You might be able to just cancel the registration and let it go back to the pool of unregistered domains. If you keep it, you should change the contact info or set it up as a private registration in order to protect your other interests.
If you were the only bidder, I would lean towards canceling it or letting it expire. If there were multiple bidders, you might want to try to sell it again on eBay.
"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote." -- Benjamin Franklin